[0001] The present invention is directed to a perfume composition comprising a methyl branched
aliphatic compound, and a method for imparting a fragrance by using such compounds
and compositions.
[0002] Up to the present, many aliphatic aldehydes or aliphatic alcohols are known to be
useful as perfume materials. For example, with respect to aliphatic aldehydes having
9-11 carbon atoms, the straight chain aldehydes are known to be useful. With respect
to aliphatic aldehydes having one branched methyl group, methylhexylacetoaldehyde
(2-methyl octanal), methylheptylacetoaldehyde (2-methyl nonanal), methyloctylacetoaldehyde
(2-methyl decanal) and methylnonylacetoaldehyde (2-methylundecanal) are known as perfume
materials. Furthermore, some aliphatic aldehydes having one branched methyl group
at the β-position to aldehyde carbon, have been reported only by D. Hagena, K. Bauer
et al. [Fragrance and Flavor Substances, 1980, D&PS, Verlag].
[0003] On the other hand, with respect to aliphatic alcohols having 9-11 carbon atoms, there
are only terpene alcohols such as linalool, geraniol, terpineol, etc., n-nonanol,
n-decanol, n-undecanol, which are known as perfume materials.
[0004] FR-A-1 562 796 relates to a perfume composition which comprises a compound of the
formula R¹R²CH(CH₂)₂CH(R³)CH₂R⁴ wherein R¹ is C₁-C₄ alkyl, R² is C₁-C₅ or phenyl,
R¹ and R² form together a four- or five-membered chain, R³ is hydrogen or methyl or
ethyl and R⁴ is CH₂OH or CHO.
[0005] It is known that the fragrances of perfume compounds are usually quite differentiated
by their differences in functional groups or by their small differences in structure.
[0006] Under these circumstances, the present inventors have synthesized many aliphatic
alcohols and aldehydes having branched methyl groups and have evaluated their fragrances
for the purpose of developing new perfumes and, as a result, found that the aliphatic
compound represented by formula (I) and having one methyl group branched at the vicinity
at the end of molecule makes the fragrance of various combination perfumes more natural-like
when they are used in perfume mixtures. The present invention was accomplished based
on the above findings.
[0007] Accordingly, the present invention provides for a combination perfume composition
which comprises a perfume base; and a fragrance emitting effective amount of a compound
selected from the group consisting of 8-methyl nonanal, 8-methyl decanal, 9-methyl
decanal, 8-methyl nonanol, 8-methyl decanol, 9-methyl decanol, 8-methyl-6-nonen-1-ol
and 9-methyl-6-decen-1-ol.
[0008] These compounds have the Formula (I)

wherein A represents a -CH₂CH₂- or a -CH=CH- group, B represents a -CH₂OH or a -CHO
group, b represents 0 or 1, a + c is 4 or 5 and a is 0 or 2.
[0009] Methyl branched aliphatic compounds (I), which are useful as a material as a component
for perfume compositions, can be prepared according to the process by the following
reaction formula:

wherein X represents a halogen atom, Ph represents a phenyl group, R represents an
alkyl group, and a, b and c have the same meaning as defined above.
[0010] Namely, methyl branched unsaturated fatty acid esters (IX) can be prepared by reacting
fatty acid esters (VI) having a halogen atom at the end of the molecule with triphenyl
phosphine to obtain phosphonium salt (VII), and running the Wittig reaction between
the resultant product and the α-methyl branched aldehyde (VIII). By reducing the methyl
branched unsaturated fatty acid ester (IX), a methyl branched aliphatic unsaturated
alcohol, which is included in the methyl branched aliphatic compound of the formula
(I), can be prepared. The methyl branched aliphatic alcohol (XI) can then be obtained
by hydrogenating compound (X); furthermore, by oxidizing compound (XI), a methyl branched
aliphatic aldehyde (XII) can be prepared.
[0011] At first, the preparation of a methyl branched unsaturated fatty acid ester (IX)
can be practiced under usual Wittig reaction conditions. Namely, compound (VI) can
be reacted with triphenyl phosphine in an inert solvent such as acetonitrile, methyl
branched aldehyde is then added, and sodium hydride is then carefully added.
[0012] The reduction of methyl branched unsaturated fatty acid ester (IX) can be preferably
practiced by using a reducing agent such as aluminum lithium hydride, or sodium borohydride.
[0013] Hydrogenation of methyl branched aliphatic unsaturated alcohol (X) can be preferably
practiced by using palladium carbon, Raney-nickel, Rubidium carbon, Rhodium carbon,
etc., as a catalyst.
[0014] Oxidation of methyl branched aliphatic alcohol (XI) can be preferably practiced by
using an oxidizing agent such as a pyridinium chlorochromate, chromic acid mixture.
[0015] The following is an exemplification of the methyl-branched aliphatic compound used
in the perfume composition according to present invention:

The amount of the methyl branched aliphatic compounds (I) in the perfume composition
of the present invention is preferably in the range of 10 ppm to 5 weight %.
[0016] Because the methyl branched aliphatic compounds of the formula (I) of the present
invention possess citrus or floral odors, as indicated in the test described below,
and because their fragrances are extremely strong, they are useful as perfume materials.
Accordingly, the perfume compositions of the present invention are applicable in a
variety of combination perfumes.
[0017] The perfume composition of the present invention can be combined into a variety of
base compounds complying with the purpose of the invention.
[Example]
[0018] The present invention is described in detail by way of the following examples and
tests.
Example 1
Preparation of 8-methyl-6-nonen-1-ol [in formula (I), A= -CH=CH-, B= -CH₂OH, a=b=0,
c=4]:
[0019] 223.12g (1 mol) of ethyl 6-bromohexanoate and 275.4g (1.05 mol) of triphenyl phosphine
were refluxed for 36 hours in 1.5 l of acetonitrile. After the reaction was terminated,
500 ml of acetonitrile was distilled off, then the reaction mixture was dried. Into
the dried mixture, 72.11 g (1 mol) of isobutyl aldehyde was added and stirred. Controlling
the reaction temperature in the range of 25-35°C, 40 g (1 mol) of oily (60%) sodium
hydride was carefully added. Then, the reaction mixture was stirred over night at
room temperature. After the reaction was ended, 500 g of water was added into the
reaction mixture, the oil layer was then separated and the water layer was extracted
twice with 300 ml of hexane. The organic layers were combined and washed with 300
ml of water, solvent was removed under reduced pressure, and then distilled under
2mm Hg to obtain 122.8 g of ethyl 8-methyl-6-nonenoate (Yield: 62% based upon the
starting material).
[0020] The product was gradually added dropwise into 1 l of dried ether solution including
11.4 g (0.3 mol) of aluminum lithium hydride under nitrogen atmosphere. The dropwise
addition was conducted while the reaction vessel was cooled sufficiently by ice water.
After the addition was completed, the reaction temperature was returned to room temperature
and stirred for 2 hours. After the reaction ended, 50 g of ethyl acetate was added
to the reaction mixture and stirred for 10 minutes. Into the reaction mixture 300
ml of water was added, and the organic layer was separated. The water layer was adjusted
to pH 7 and extracted three times with 200 ml of diethyl ether. The organic layers
were combined and washed with 200 ml of water, and solvent was removed under reduced
pressure to obtain 93.8 g (Yield 97%) of 8-methyl-6-nonen-1-ol.
Boiling Point: 82°C/3mm Hg
IR (liquid film, cm⁻¹): 3344, 2932, 1656, 1462, 1378, 1362
¹H-NMR (CDCl₃ solvent, TMS internal standard, δ):
0.94 (doublet, 6H, J=6.6Hz)
1.25-1.75 (multiplet, 7H)
1.92-2.15 (multiplet, 2H)
2.40-2.70 (multiplet, 1H)
3.63 (triplet, 2H, J=6.2Hz)
5.04-5.34 (multiplet, 2H)
MS(m/e, relative intensity): 69(100), 57(93), 67(83), 82(78),
81(77), 95(72), 41(65), 56(47), 68(34), 57(33)
Example 2
Preparation of 8-methyl nonanol [in formula (I), A= -CH₂CH₂-, B= -CH₂OH, a=b=0, c=4]:
[0021] 93.8 g of 8-methyl-6-nonen-1-ol, which was prepared in example 1, and 14.1 g of 5%
Palladium carbon were agitated for 1 hour in an autoclave at a reaction temperature
of 60°C under 100 kg/cm² of hydrogen pressure. After the reaction ended, Palladium
carbon was filtered off to obtain 91.0 g of 8-methyl nonanol (Yield 95.8%).
Boiling Point: 87°C/2.5 mmHg
IR (liquid film, cm⁻¹): 3340, 2927, 1467, 1384, 1367
¹H-NMR (CDCl₃ solvent, TMS internal standard, δ):
0.85 (doublet, 6H, J=6.2 Hz)
1.15-1.70 (multiplet, 7 H)
3.62 (multiplet, 2H)
MS(m/e, relative intensity): 56(100), 69(76), 55(69), 57(56),
43(36), 84(28), 97(23), 68(14)
Example 3
Preparation of 8-methyl nonanal [in formula (I), A= -CH₂CH₂-, B= -CHO, a=b=0, c=4]:
[0022] 91.0g of 8-methyl nonanol, which was prepared in Example 2, was added dropwise into
a mixture solution of 1.5 l of dichloromethane and 194 g (0.9 mol) of pyridinium chlorochromate,
and the mixture was stirred for 2 hours at room temperature. Into the reaction mixture
3 l of diethyl ether was added, the mixture was passed through 500 g of florisil and
solvent was evaporated off. The crude product obtained was distilled to obtain 77.5
g of 8-methyl nonanol (Yield 86.3%). Boiling point: 66°C/2 mmHg.
IR (liquid film, CM⁻¹): 2950, 1730, 1470, 1385, 1375
¹H-NMR (CD Cl₃ solvent, TMS internal standard, δ):
0.87 (doublet, 6H, J=6.2Hz)
1.20-1.72 (multiplet, 11H)
2.43 (triplet, 2H, J=7.5Hz)
9.76 (triplet, 1H, J-1.8Hz)
MS (m/e, relative intensity): 57(100), 82(65), 43(57), 69(55),
55(52), 56(49), 41(48), 72(42), 81(38), 95(37)
Reference Example 1
Preparation of 7-methyl-5-decen-1-ol [in formula (I), A= -CH=CH- B= -CH₂OH, a=2, b=0,
c=3]:
[0024] 104.54 g (0.5 mol) of ethyl 5-bromovalerate and 137.5 g (0.525 mol) of triphenyl
phosphine were refluxed for 36 hours in 1 l of acetonitrile. After the reaction terminated,
500 ml of acetonitrile was distilled off, then the reaction mixture was dried. Under
nitrogen atmosphere, 50.1 g (0.5 mol) of 2-methyl valeraldehyde was added, then the
reaction mixture was stirred. Controlling the reaction temperature to within the range
of 25-35°C, 20.0 g (0.5 mol) of oily (60%) sodium hydride was added little by little.
After the addition, the reaction mixture was stirred over night at room temperature.
After the reaction ended, 250 g of water was added into the reaction mixture, then
oil layer was separated and the water layer was extracted three times with 150 ml
of hexane. The organic layers were combined and washed with 150 ml of water. After
the hexane solution was dried sufficiently with anhydrous Magnesium sulfate anhydrate,
solvent was removed under reduced pressure, and distilled to obtain 57.3 g of ethyl
7-methyl-5-decenoate (Yield: 54%, based upon starting material). The product was gradually
added dropwise into 500 ml of dried ethylether solution including 5.12 g (0.135 mol)
of aluminum lithium hydride under nitrogen stream. The dropwise addition was done
while a reaction vessel was cooled sufficiently by ice water. After the addition was
completed, the reaction temperature was returned to room temperature and stirred for
2 hours. Then, 300 ml of water was added gradually into the reaction mixture, and
the organic layer was separated. The water layer was returned to pH7 and extracted
three times with 100 ml of diethylether. The organic layers were combined and washed
with 100 ml of water, and solvent was removed from the reaction mixture under reduced
pressure to obtain 44.2g of 7-methyl-5-decen-1-ol (Yield: 52'', based upon starting
material).
IR (liquid film, cm⁻¹): 3345, 2958, 1457, 1066
¹H-NMR (CDCl₃ solvent, TMS internal standard, δ):
0.88 (triplet, 3H)
0.92 (doublet, 3H, J=6.6Hz)
1.15-1.35 (multiplet, 4H)
1.40-1.68 (multiplet, 5H)
1.96-2.15 (multiplet, 2H)
2.20-2.58 (multiplet, 1H)
3.36-3.70 (multiplet, 2H)
5.00-5.45 (multiplet, 2H)
MS (m/e, relative intensity): 67(100), 109(93), 55(90), 81(76),
95(42), 68(31), 41(30), 56(22), 82(20), 84(20)
Reference Example 2
Preparation of 7-methyl decanol [in formula (I), A= -CH₂CH₂-, B= -CH₂OH, a=2, b=0,
c=3]:
[0025] 44g (0.26 mol) of 7-methyl-5-decen-1-ol, which was prepared in Reference Example
1 and 6.6 g of 5% Palladium carbon were agitated for 1 hour in an autoclave at a reaction
temperature of 60°C under 100 kg/cm² of hydrogen pressure. After the reaction ended,
Palladium carbon was filtered off to obtain 7-methyl decanol.
Amount: 43.5 g (Yield 97%)
Boiling point: 93°C/3 mmHg)
IR (liquid film, cm⁻¹): 3340, 2926, 1463, 1378, 1058
¹H-NMR (CDCl₃ solvent, TMS internal standard, δ):
0.80-0.95 (multiplet, 6H)
1.18-1.70 (multiplet, 16H)
3.67 (triplet, 2H, J=6.3Hz)
MS (m/e, relative intensity): 69(100, 55(71), 84(49), 43(48),
70(43), 111(35), 56(33), 41(32), 83(29), 71(23)
Reference Example 3
Preparation of 7-methyl decanal [in the formula (I), A= -CH₂CH2-, B= -CHO, a=2, b=0,
c=3]:
[0026] 43.5 g (0.25 mol) of 7-methyl decanol, which was prepared in Example 5, was added
into a mixture solution of 500 ml of dichloromethane and 81.9 g (0.38 mol) of pyridinium
chlorochromate, and the reaction mixture was stirred for 2 hours at room temperature.
Into the reaction mixture 2 l of diethyl ether was added, the mixture was passed through
300 g of florisil, and then solvent was evaporated off. The crude product obtained
was distilled to obtain 7-methyl decanal.
Amount: 31.1 g (Yield: 73%):
Boiling point: 83.5°C/4 mmHg)
IR (liquid film, cm⁻¹): 2932, 1729, 1466, 1379
¹H-NMR (CDCl₃ solvent, TMS internal standard, δ):
0.8-0.92 (multiplet, 6H)
1.20-1.80 (multiplet, 13H)
2.43 (triplet, 2H, J=6.6Hz)
9.76 (triplet, 1H, J=1.8Hz)
MS (m/e, relative intensity): 109(100), 43(92), 55(88), 57(73),
84(71), 67(67), 41(58), 71(52), 85(50), 83(39)
Example 4
Preparation of 9-methyl-6-decen-1-ol [in formula (I), A= -CH=CH-, B= -CH₂OH, a=0,
b=1, c=4]:
[0028] 9-methyl-6-decen-1-ol was prepared in the same manner according to Reference Example
1 except that 111.56 g (0.5 mol) of ethyl 6-bromohexanoate was used in place of ethyl
5-bromovalerate and 43.07 g (0.5 mol) of isovaleraldehyde was used in place of 2-methyl
valeraldehyde.
Amount: 42.6 g (Yield: 50%, based upon starting material)
IR (liquid film, cm⁻¹): 3336, 2932, 1465, 1383, 1363, 1055
¹H-NMR (CDCl₃ solvent, TMS internal standard, δ):
0.89 (doublet, 6H, J=6.2Hz)
1.24-1.64 (multiplet, 9H)
1.80-2.05 (multiplet, 3H)
3.62 (triplet, 2H)
5.32-5.45 (multiplet, 2H)
MS (m/e, relative intensity): 67(100), 55(65), 81(56), 95(48),
82(46), 69(41), 68(38), 41(37), 56(33), 43(30)
Example 5
Preparation of 9-methyl decanol [in formula (I), A= -CH₂CH₃-, B= -CH₂OH, a=0, b=1,
c=4] and 9-methyl decanal [in formula (I), A= -CH₂CH₂-, B= -CH0, a= 0, b= 1, c= 4]:
[0029] 42.6 g (0.25 mol) of 9-methyl-7-decen-1-ol, which was prepared in Example 5, was
hydrogenated according to Reference Example 2 to obtain 9-methyl decanol (amount:
41.8 g, yield: 97%). The alcohol was oxidized according to Reference Example 3 to
obtain 9-methyl decanal.
Amount: 34.3 g (Yield: 83%)
Boiling point: 77°C/3 mmHg
IR (liquid film, cm⁻¹): 2927, 1730, 1467, 1386, 1367
¹H-NMR (CDCl₃ solvent, TMS inner standard, δ):
0.86 (doublet, 6H, J=6.2Hz)
1.20-1.70 (multiplet, 13H)
2.43 (triplet, 1H, J=6.4Hz)
9.76 (triplet, 1H, J=2.0Hz)
MS (m/e, relative strength): 57(100), 43(74), 69(69)
Test 1
[0030] The fragrances of the methyl branched aliphatic compounds (I), which are combined
into the perfume composition of the present invention, were examined. The results
are shown in Table 1.
Table 1
| Compound of the formula (I) |
odor description |
| 8-methyl nonanal |
citrus, sweet, waxy, milky |
| 9-methyl decanal |
green, fatty, aldehyde |
| 8-methyl nonanol |
green, fatty, floral, rosy |
| 9-methyl decanol |
fatty, oily |
[0031] From Table 1, the fragrance of the aldehydes having a branched methyl group according
to the present invention has, in comparison with the aldehydes without a branched
methyl group, a characteristic smell which is reduced with respect to the particular
aldehyde odor and enhanced with respect to the particular citrus and floral odors.
The fragrances of the methyl branched alcohols also have strong floral, fruity and
green leafy odors, unlike the usual alcohols.
Test 2
[0032] In order to evaluate the strength of the fragrance, the odor threshold of the fragrance
was measured by ten professional panelists.
〈test method〉
[0033] The odor threshold was evaluated by using the method of triangle comparison (answer
one).
〈test result〉
[0034] The result regarding 8-methyl nonanal is described below. 2-methyl decanal and n-undecanol
were used as comparative samples. Though the odor threshold of 2-methyl decanal and
n-undecanol were both 5.0 ppm, the odor threshold of 8-methyl nonanal of the present
invention was 0.01 ppm.
Example 6
[0035]
| ROSE BASE: |
(parts by weight) |
| geranium bourbon |
10 |
| citronellol |
100 |
| geraniol |
50 |
| nerol |
30 |
| phenylethyl alcohol |
600 |
| diphenyl oxide |
5 |
| linalool |
15 |
| geranyl acetate |
10 |
| eugenol |
10 |
| decenol |
1 |
| phenylacetic acid 9.9% (phenylethyl alcohol) |
10 |
| methyl phenylacetate |
20 |
| bees wax absolute |
5 |
| dipropylene glycol |
124 |
| TOTAL |
990 |
[0036] Into 990 parts by total weight of rose base described above, 10 parts by weight of
8-methyl-6-nonen-1-ol was added, and ten professional panelists evaluated the added
composition of the present invention and non-added comparative composition. All ten
panelists found that the composition of the present invention has a stronger and enhanced
natural floral rose base odor.
Example 7
[0037]
| MANDARIN BASE: |
parts by weight |
| α-pinene |
20 |
| β-pinene |
10 |
| myrcene |
10 |
| limonene |
484 |
| lemon terpene |
100 |
| orange valencia |
200 |
| γ-terpinene |
150 |
| mandarin aldehyde 10(%)* |
10 |
| thyme red |
5 |
| dimethyl anthranilate |
5 |
| coumarin |
1 |
| carrot seed oil |
1 |
| geranyl methyl carbinyl acetate |
2 |
| TOTAL |
998 |
| * produced by Firmenich SA specialty chemical cis -3-dodecenal |
[0038] Into 998 parts by total weight of Mandarin base described above, w parts by weight
of 8-methyl nonanal was added, and ten professional panelists evaluated the added
composition (the present invention) and non-added comparative composition. Nine panelists
found that the composition of the present invention has much peel-like feeling and
enhanced natural citrus odors.
[Effect of the Invention]
[0040] Methyl branched aliphatic compounds (I) of the present invention have citrus, floral,
green or fruity fragrances, and the fragrances are extremely strong. Therefore, the
perfume composition of the present invention comprising a methyl branched aliphatic
compound (I) can emit, for example, much peel-like odor to reach a more natural citrus-like
perfume composition, and emit a sweet odor to reach a more natural floral-like perfume
composition; and furthermore, emit a more transparent feeling as to a fruity perfume
composition. Accordingly, the perfume composition of the present invention is superior
as a material for a variety of combinations, and widely applicable to combination
perfumes for dishwasher detergents, heavy duty detergents, softeners, fragrant agents,
shampoos, rinses, cosmetics, soaps, etc.